Dovetail-mortising machine



(-No Model.)

2 Sheets3heet 1 0. GRISTADORO. DOVETAIL MORTISING MACHINE.

Patented Dec. 31, 189 5.

Z;?/VeIZZ07"-' 072627166 016ml" an v w ANDREW EGRANAM. PHOTOUTHQWASHINGION. l7

UNITED STATES PATENT OFFICE.

CHARLES CRISTADORO, OF ST. PAUL, MINNESOTA.

DOVETAIL-MORTISING MACHINE.

SPECIFICATION formingpart of Letters Patent No. 552,351, dated December 31, 1895.

Application filed July 15, 1892. Serial No. 440,136. (No model.)

To all whom it may concern:

Be it known that I, OHARLEs CRISTADORO, of St. Paul, Ramsey county, Minnesota, have invented certain Improvements in Dovetail- Mortising Machines, of which the following is a specification.

My invention relates to improvements in machines designed to cut mortises in the ends of the sides of box-boards to receive corresponding tenons upon the end boards of the box, its object being to provide an improved machine adapted to cut a series of mort-ises in a plurality of boards in one operation.

To this end my invention consists in providing a gang of cutters adapted to cut straight grooves with parallel sides in the stock as passed over them. Arranged to travel past these bits is the slidable frame or clamp having rocking an gle-blocks on opposite sides, between which the boards are placed and held at the same angle with the path of the cutters as the desired dovetail angle of themortise to be cut. WVhen thus placed, the boards are clamped and held firmly in position so that the grooves cut may be absolutely unvarying. The first part of the operation being completed, which consists of the cutting of the series of grooves with thetravel of the stock over the cutters, the clamp is loosened and the angle-blocks reversed so as to turn and hold the stock at an exactly opposite angle, the clamp being again tightened. The frame or table is provided with shifting devices whereby the frame with its load can be moved laterally to compensate for the variation between the positions of the grooves first cut in the boards, with the path of the cutters, so that on the reverse movement of the stock in the second part of the operation the cutters will enter the throats or adjacent ends of the grooves cut in each board and cut away one of the side walls of the grooves so as to shape them into the required dovetail form.

My invention further consists in the specific construction and combination hereinafter described, and particularly pointed out in the claims.

In the accompanying drawings, forming part of this specification, Figure 1 represents a plan view of my device, showing the position of the clamping-frame in which the stock is held in relation to the cutters, and

the clamping attachments therefor, and the means for shifting the frame laterally. Fig. 2 is a side elevation ofthe same. Fig. 3 is a plan view of the clamping-frame, one position of the stock being indicated by full lines and the reverse position by dotted lines, and Figs. 4, 5, 6, and 7, respectively, illustrate diagrammatically the position of the stock when adjusted to receive its first cut, its posit-ion when tilted to the opposite angle, its position when laterally shifted to bring the openings of the grooves out by the first operation into line with the cutters, and the form of the mortises cut by the two operations therein.

In the drawings, 2 represents the bed of the machine, upon which the table A is arranged to slide laterally in suitable guides 3. At the sides of the table are arranged the stops 4 and 5 limiting its lateral movement. The lever 6, pivoted to the bed of the machine and connected by the link 7 to the table, serves to move the same laterally between the stops, as hereinafter described. Mounted upon the table A to slide longitudinally of the machine is the frame B. The clamp-screw 8 provided with the hand-wheel 9, mounted upon the table A and threaded into the table B, serves to drive the table B along the frame Ain the operation of the machine. Upon the table B is mounted the clamping-frame 0, consisting preferably of the side bar 10 and the end pieces 11 rigidly secured to and formed integral with the bar 10 and at right angles therewith. The bar or frame-piece 12, parallel with the piece 10, slides on guides 13 to and from the piece 10, so as to vary the width of the frame, the springs 14 between the members tending to throw the movable piece 12 outward. Pivoted securely to the members 10 and 12 at or near their centers are the rocking angle-blocks 15 in the form of isosceles triangles, the equal angles of which correspond to the angle of the dovetail to be cut in the stock. Between these blocks are placed boards or pieces of stock 16 which are firmly secured in the required angular position by means of the eccentric roll or cylinder 17, arranged parallel with the bar 12 and provided with the handle 18, by means of which it may be turned in its hearings to crowd the bar 12 inward against the tension of the springs and firmly clamp the stock between the blocks. In orderto hold the stock in contact with one of the end pieces or bars 11, so that the notches or mortises cut therein shall be at exactly the same distance from the edge of all the boards, I arrange a set-screw 15) in one of the end frame-pieces adapted to bear upon the follower 20, arranged transversely in the frame and bearing upon the sides of the stock, thus pressing them against the opposite end of the frame and holding them in contact with it. Arranged in suit able bearings (not shown) upon the machine are the series of cutters 21, which project upward through the slotted openings 22 in the table B, so as to be brought in contact with the stock held in the frame C and cut a series of grooves in the stock as it is carried by the table 13 over them.

In Figs. 4, 5, 6, and 7 are illustrated the different positions of the stock in relation to the cutters and the work done by them therein. Fig. 4 illustrates the position of the stock to receive the first cut, the angular position being indicated by the dotted lines in Fig. 3. The paths of the cutters 21 are indicated by the dot-and-dash lines, and with the first part of the operation the straight grooves are cut through the series of boards, which, being placed at an angle with the plane of the cutters, the grooves out are at the same angle through them. After the first cut the lever 18 is turned to release the clamp and the setscrew 10 loosened, when the angleblocks may be rocked, carrying the stock into the position illustrated in Fig. 5. It is evident that the openings or ends of the notches on the sides of the boards toward the cutters will then be out of alignment with them, and the stock must consequently be moved laterally to bring them into alignment, which adjusted position is illustrated in Fig. (5. The stock being then carried past the cutters, they cut away one wall of the notches in the boards, as indicated by the dot-and-dash lines, thus forming the dovetail notches 24, as shown clearly in detail Fig. 8, adapted to receive corresponding tenons on the outer box-boards.

I claim- 1. lhe combination with the series of groove cutters, of means for presenting a plurality of pieces of stock to said cutters whereby a series of parallel grooves is out in the edges of the stock, means for shifting all of said stock to a predetermined angle with its first position, for shifting each piece laterally with reference to the adjacent pieces, and for laterally shifting the position of all the stock with reference to the cutters, whereby in presenting the same a second time to said cutters one side of the grooves in the several pieces of stock is cut away to form similar dovetail notches, substantially as described.

2. The combination with the series of groove cutters, of means for holding a plurality of pieces of stock at a predetermined angle with the path of the cutters, means for shifting said angle a predetermined degree, means for uniformly shifting the several pieces of stock laterally with reference to each other a predetermined distance, means for laterally shifting all of the stock a predetermined distance, and means for presenting said stock to said cutters, substantially as described.

The combination with the clamp, of the angle blocks respectivelypivoted to the members of the clamp and adapted to be set to hold the stock in either of two similar but opposite angular positions, and the follower and its screw adapted to hold the stock against one end of said clamp, substantially as described.

In testimony whereof I have hereunto set my hand this 11th day of July, 1892.

CHARLES ORICTADORO.

In presence of- T. D. MERWIN, II. S. J OHNSON. 

